Novel capsule finishing apparatus

ABSTRACT

Apparatus and means are provided for finishing pharmaceutical capsules under vacuum whereby any empty capsules present are disqualified and dust and other contamination are cleared from the surfaces of capsules, capsule filling machinery, etc.

Waited States Patent 11 1 [111 Mamas Garland June 1'12, 11973 1 1 NOVELCAPSULE FINISHING APPARATUS [56] References Cited [76] Inventor: Carl C.Garland, 15700 Kentfield, UNITED STATES PATENTS Detroit, Mich. 482233,612,271 10/1971 Behling 209/115 X [22] Filed July 17 1972 3,097,1617/1963 Dudyak .1 209/137 X [21] Appl. N0.: 272,185 PrimaryExaminer-Allen N. Knowles Att0rneyR0bert R. Adams. David B. Ehrlinger,Related Apphcanon Data George M. Richards and Edward J. Gall [62]Division of Ser. No. 88,053, Nov. 9, 1970, Pat. No.

316931320 57 ABSTRACT 52 U.S. c1 209 74 209/115 209/121 AWarm"s andmeans are Provicied finishing P 51 Int. Cl B(17b 13/10 maceutica'capsules under vacuum whereby any empty [58] Field of search 209/115 74137 capsules Pmsent are disqualified and dust and other 7 1 1contamination are cleared from the surfaces of capsules, capsule fillingmachinery, etc.

3 Claims, 7 Drawing Figures NOVEL CAPSULE FINISHING APPARATUS This is adivision, of application Ser. No. 88,053, filed Nov. 9, l970, now U.S.Pat. No. 3,693,320.

SUMMARY AND DETAILED DESCRIPTION This invention relates to novelapparatus and means for finishing filled pharmaceutical capsules. Moreparticularly, the invention relates to finishing apparatus forprocessing joined capsules in a vacuum to reject defective capsules andeliminate surface powders and the like.

Heretofore the prior art has had the problem of keeping the filling roomin good order and free of spillage. Another problem has been that ofcleaning filled capsules so that excess material used for filling iscompletely removed from the capsule exterior in order that the same willhave a pleasing appearance and will be free of the taste and odor of theproduct; One methodfor cleaning capsules involves agitating the filledcapsules in a bed of common salt. The cleaning action in this case isdue to presence of moisture in the salt which serves to absorb or takeup surface dust, leaving the capsule wall clean. While the prior artcleaning action is useful, the method is cumbersome to operate and itfails to disqualify or reject capsules which are not completely joinedor are defective due to the presence of cracks or holes in the capsulewall. The prior art method also suffers from the disadvantage thatunless done promptly after filling, the excess filling material maybecome permanently impregnated into the capsule wall or may absorbmoisture which in turn may adversely affect the capsule wall.

It is therefore an object of the present invention to provide improvedmeans for finishing and cleaning hard shell gelatin capsules filled witha granular or powdered material or other pharmaceutical fill.

It is another object of the invention to provide means for disqualifyingdefective capsules of the kind mentioned.

Another object is to provide controlled air cleaning means for finishingfilled capsules.

Still another object is to provide means for ridding the filling area ofexcess dust, powder spillage, etc.

These and other objects, purposes and advantages of the invention willbe seen from the following description and the accompanying drawing inwhich:

FIG. 1 is a side view of a cleaning assembly according to the invention;

FIG. 2 is a top view of the assembly taken on line 22 of FIG. 1 showinga vacuum chamber in combination with a filling chute for the chamber;

FIG. 3 is a detailed illustration of the filling chute;

FIGS. 4 and 4a are views of the vacuum chamber inlet.

FIG. 5 is a view, partly in section, of a shell remover according to theinvention; and

FIG. 6 is an end view of the shell remover.

The preferred apparatus illustrated in FIG. 1 includes a vacuum chamber10, a filler housing 30, and a transfer chute 40. The chamber 10 has acylindrical head 11 which merges with a conical or funnel-shaped body 12having an access opening or orifice 13 at its lower end. The chamber 10includes a flat circular top 14 with a central exhaust opening or port15. The top 14 is removably attached to the head 11 by any suitablemeans such as tie rods 16 and retaining wing nuts 17. The underside ofthe top is provided with an integral conical screen or baffle 19 mountedunder and spanning the exhaust opening 15. The baffle walls 21 areslanted symmetrically away from the center axis (preferably at an angleof about 30 to 50 from the vertical axis) and have an open meshstructure or evenly spaced perforations 22. For convenience, the top 14and baffle 19 are removable as a single unit so that the baffle walls 21are directly exposed for cleaning. Mounted above and in communicationwith the exhaust port 15 is a conduit and T-valve 26 connected with asuitable vacuum source for exhausting air in the direction shown byarrow 29. In one preferred embodiment, the source is a commerciallyavailable vacuum cleaner supplied under the name Toronado (rated at 5H.P., Breuer Electrical Mfg. Co., Chicago, Illinois, U.S.A.) andarranged to draw on a 1.5 inch flexible corrugated conduit; the exhaustport, body, and inlet 13 measure approximately 1.5, 6, and ll inches,respectively. When the valve 26 is in the open position so that a vacuumis drawn on the chamber, air from the atmosphere is pulled into thechamber through inlet 13 and carried via body 12 upward through the headportion 11, and out of the chamber through the baffle perforations andexit port 15. A preferred feature of the chamber is the symmetricalfunnel-shape of the body which advantageously serves to provide agradually decreasing linear velocity of air flow in the direction fromthe opening 13 to the head portion, which in turn facilitates theuniform vertically cyclic flow of capsules while being processed in thechamber. When the valve 26 is in the off position so that the vacuumsource is cut off, atmospheric air enters in the direction shown byarrow 20 through the T-valve into the chamber.

The housing 30 is adapted to be mounted by suitable bracket means aroundthe filling apparatus. The apparatus may be any suitable capsule fillingmeans having work positions where capsules are filled and joined andwhere there is a problem of dust removal, examples of such apparatusbeing Hofliger-Karg Type GKF700, Zanasi Model Z-25 and MG-Z Model G-36.The apparatus illustrated comprises conventional filler components ofaModel 8 filler, Parke, Davis & Company, Detroit, Michigan, USA. Thelatter has an ejector ring 32 and an ejector plate 36 arranged forpivoting to a position face-to-face in cooperation with parallel guiderods 37. The space between the ring 32 and plate 36 is sufficient toaccommodate placing the edges of the joining rings (not shown) onto theguide rods, in juxtaposition with the ring and plate. The ejector ringis power-driven to reciprocate axially back and forth by dwellfoot-switch means under control of the operator, the shift in movementbeing sufficient (after the operator lines up the ejector fingers 32awith the joining ring channels) for the ejector fingers 32a to enter andthen to be withdrawn from the channels. The housing 30 has an open top33 and funnel-like bottom 34 with a dropout opening 35 matching themouth 42 of the transfer chute .40. The housing 30 includes arms 38 atits lower end adapted for holding the transfer chute 40 in position. Theejector plate 36 is mounted, in conventional fashion, for rotation backand forth from the standby position (as illustrated) to the operatingposition (shown in dotted outline). The gate 26 and the chute 40 operateoff shaft means power-driven by separate air pressure cylinders forsynchronous rotation to vacuum and transfer positions, respectively,whenever the ejector plate is placed in the standby position. By thesame means, the gate and the chute are returned to their standby orholding positions whenever the ejector plate is pivoted to the operatingposition. Since delays often occur in the filling operation, theapparatus may optionally include automatic timing and control means forreturning the gate and chute to their standby positions upon expirationof a predetermined time interval, e.g., after one minute has elapsed.

The transfer chute 40 is mounted by pivot shaft means 41 to rotate asindicated between the mentioned transfer position and the hold positionshown in dotted outline. The upper end of the chute 40 has the mentionedopen-mouth 42 bounded on its lower margin by a holding surface 420; thelower end has a discharge opening 43. The mouth 42 and the holdingsurface 42a have dimensions matching the drop-out opening 35. Thedischarge opening 43 is formed to provide a close fit with the inletedges 13a of the lower end of the chamber. The chute has a transfer stop45 and a holding stop 46 to constrain or limit the pivot movementbetween the transfer and holding positions.

While the invention contemplates the aforementioned means of emptyingimproperly joined or defective capsules, it also contemplates means forsingling out, disqualifying and removing empty capsule shells andcapsule parts, capsule fragments and the like. To this end, shellremover means 50 (FIGS. 5 and 6 illustrating a preferred embodiment) isprovided. The shell remover constitutes a tunnel overlying a conveyor 51defining the path of travel of capsules. The tunnel includes a hoodpiecewhich has side walls 53a and 53b, a top 54, an open entrance end 55, andan open exit end 56. Mounted on the top of the hoodpiece and extendingupward from the periphery of an exhaust opening 57 is a chimney 58arranged in communication with a vacuum source. The hoodpiece isremovably mounted for vertically adjustable positioning upon theconveyor by means of the mounting slots 59, threaded studs 60, and wingnuts 61. The bed or floor of the conveyor includes a uniform pattern ofopenings 62, slots or the like arranged to provide passageway means forupward air flow particularly throughout the tunnel floor. The conveyor51 is preferably a conventional airdriven vibratory chute or equivalentconveyor means. The configuration and dimensions of the tunnel can bevaried to meet changing requirements such as the size and filled weightof capsule being processed. In one embodiment, for example, using No. 1lactose-tilled capsules at a flow rate of about 600 capsules per minuteand operating with a vacuum equivalent to about 10-15 inches of water,the tunnel is about 1 inch wide, the opening 57 is rectangular measuring1 it; by 2 inches, and is located about 2 '75 inches from the entranceopening 55 and l inch from the exit opening. The height is adjustablewithin a range from about to l a; inch. The openings in the conveyorfloor within the tunnel are 0.156 inches in diameter spaced on 3/16 inchcenters to provide about 60 percent void in the surface.

OPERATION The operation of producing finished capsules with the meansillustrated has what may be regarded as four steps: joining andejecting, transferring the joined capsules to the vacuum chamber,cleaning the capsules while in the chamber, and collecting the cleanedcapsules. Referring to these steps in detail, the joining rings (bodyring with filled bodies and cap ring with empty caps) are manuallytransferred as a unit from the filling work station, placed on the guiderods 37 body ring first and adjusted face-to-face with the ejector ringso that the ejector fingers are in alignment with the joining ringchannels. The ejector plate 36 is manually pivoted to the operatingposition (dotted outline, FIG. 1) which pivoting action by the mentionedswitch and pneumatic means causes the valve gate 26 and chute 40 to moveto their holding positions whereby vacuum in the chamber is broken.

Next, the ejector ring fingers are advanced into the joining rings bythe mentioned power means causing the capsules to be joined. Theoperator then causes the ejector ring to retract, at the same timeadvancing the joined rings manually in phase with the ejector ring sothat the joined capsules are ejected. As the capsules eject, they fallinto the housing 30 and slide by gravity towards the drop-out openingwhere they are restrained by the holding surface 42a of the chutestanding as it does in the position illustrated in dotted outline inFIG. 1. In this position the valve 26 is in the vacuum off positionillustrated. The operator then manually rotates the ejector plate 36clockwise back to the standby position. This movement automaticallycauses the chute and the valve to return to the transfer and vacuumpositions. When this happens the unloaded capsules in the lower end ofthe housing, no longer restrained by the holding surface 42a, freelyslide through the chute towards the discharge port 43. At the same timea vacuum in suddenly drawn on the chamber which action serves to exhaustair through baffle 19 from the interior of the chamber. This, in turn,causes a suction effect on the capsules drawn through the discharge port43 causing them to become airborne and to be pulled upwardly through theinlet opening 13 into the chamber 10, first through the body 12 and thenupward into the head 11. In this area they move vertically upward in aline, impinge upon the slant walls 21 of the baffle and fall back asillustrated by the dotted arrows of FIG. 1.

Meanwhile, the discharge opening 43 has been seated against the edges13a of the inlet opening 13 so that the same is sealed. However, theseal purposely allows some air to enter which air serves to lift andmove the capsules. As intended, the air is continuously being exhaustedfrom the chamber, and correspondingly the capsules are in constantmovement in the chamber, first rising and then falling back. As thecapsules fall back they move against the oncoming flow of air. The airchamber pressure, however, is less than atmospheric since the inletopening 13 restricts entry of air. In this way a sufficient vacuum iscreated in the chamber to cause the separation of any loose powder orparticulate matter from the outer surfaces of each capsule. Such powderand foreign matter are carried upward through the low pressure airstream through the perforations 22 of the baffle and out of the chamberthrough the exhaust port. At the same time any capsules which aredefective (with cracks or holes in the wall, poorly joined or otherwisesubject to loss of the powder fill) are caused by the vacuum cleaningaction to become gradually emptied: the fill is slowly lost due to thecontinuing cleaning effect until nothing but the empty capsule shellremains.

The slant walls 21 of the baffle provide a useful agitation effect. Inthis regard, the capsules in the chamber are continuously cycled againstthe baffle walls 21 in turbulent fashion during the period of thecleaning cycle. As the capsules strike the baffle, they abruptly undergoa change of direction whereby surface dust is in effect shaken loose andcarried straight on through the baffle by way of the perforations. Afterstriking the baffle the capsules rebound and in the usual case movelaterally and strike the chamber walls, the impact of which also has theeffect of jarring surface dust loose. The mentioned impact action servesnot only to remove unwanted particulate matter but also to separateloosely joined or improperly joined capsules and it follows that theseare emptied in due course, leaving the empty shells in the chamber.Advantageously, the vacuum action also has a useful cleaning effectoutside the chamber in that dust-laden air at the filling work stationtends to gravitate and move downward through housing 30 and chute 40. Bythese means, throughout the operation, the environment is constantlybeing cleared of residual powder. Also, if desired, the operator canoccasionally dust off the apparatus directly into the housing with theassurance that the unwanted dust will be purged automatically andcarried away in the vacuum cycle.

The vacuum cycle continues until the operator activates the ejectorplate to the down position (or until the mentioned automatic timer meansbypasses the operation and terminates the vacuum cycle) at which timethe valve gate 26 and chute 40 are phased into the unload position. Whenthis occurs the vacuum is broken and air enters the chamber via theinlet opening and valve (in the direction of arrow 20). With the loss ofthe vacuum in the chamber the capsules, now clean, fall by gravityaction downward through the access opening into a suitable collector,conveyor, or the like.

Capsules processed in the cleaner or other work station are according tothe invention transferred directly or indirectly to the shell removermeans 50 (arrow D, FIG. 5) along the path of the conveyor 51. Forsimplicity, the conveyor is a rigid trough constructed of stainlesssteel or other suitable material, operating as part of a vibratory feedbowl. The path of travel of filled capsules passes through the tunnelunder vacuum to the exit end of the conveyor (arrow F, FIG. 5). Theconstruction of the tunnel is such that the air flow to the chimney 58from the exit end 56 is greater than the air flow from the entrance end55 thereby creating a back pressure or air curtain inside the tunnel atthe exit end. Empty capsules, therefore, and capsule shell parts movingwith the filled capsules are according to the invention unable to passthe tunnel because of the selective exhaust effect and back pressure. Inthis regard, the shells entering the tunnel either are sucked updirectly into the chimney 58 or are rebuffed by the air curtain at theexit end 56 and carried back to the chimney where the shells are removedby vacuum for salvage. The exhaust action is enhanced by the aperturing62 in the conveyor which serves in the tunnel area to facilitate gettingthe shells airborne and separated from the filled capsules. The shellremoving effect is highly efficient. It is not unusual, for example,that a capsule shell will enter the tunnel, pass the chimney and move upto the exit end at which point it will suddenly, as if meeting a solidsurface, bounce back and up to the chimney 58. The strength of theexhaust action and back pressure can be varied, depending onrequirements of capsule size, capsule weight, etc., by adjusting therelative position of the hood-piece 52. The en trance and exit openingsof the tunnels in this way can be separately changed. Other equivalentmeans for modifying the differential air flow will be satisfactory.

While the invention in capsule handling systems has been described inconsiderable detail in the foregoing specification, it will be realizedby those skilled in the art that wide variation can be made in suchdetail within the spirit of the invention claimed below; it is intendedthat the claims be interpreted to cover both the invention particularlydescribed and any such variation.

I claim:

1. A capsule shell remover comprising tunnel means having overheadvacuum exhaust means and open entrance and exit ends, and meansincluding a perforate floor for conveying filled capsules, emptycapsules and the like in a linear path through the tunnel means via theopen ends and below the exhaust means, the exhaust means includingaperture means adapted to draw air into the tunnel from both open endsand through openings in the floor, with sufficient force to cause emptycapsule parts in the tunnel to become air lifted and exhausted via theaperture means, the aperture means being located intermediate the openends in a position such that the air flow thereto from the exit end isgreater than that from the entrance end whereby a back pressure isdeveloped sufficient to cause empty capsules and capsule parts to bedrawn into the exhaust aperture and prevented from passing through thetunnel means.

2. A shell remover according to claim 1 wherein the exhaust aperturemeans is positioned downstream of the midpoint between the open ends ofthe tunnel means.

3. A shell remover according to claim 1 including means of adjusting thesize of the tunnel end openings. =1:

1. A capsule shell remover comprising tunnel means having overhead vacuum exhaust means and open entrance and exit ends, and means including a perforate floor for conveying filled capsules, empty capsules and the like in a linear path through the tunnel means via the open ends and below the exhaust means, the exhaust means including aperture means adapted to draw air into the tunnel from both open ends and through openings in the floor, with sufficient force to cause empty capsule parts in the tunnel to become air lifted and exhausted via the aperture means, the aperture means being located intermediate the open ends in a position such that the air flow thereto from the exit end is greater than that from the entrance end whereby a back pressure is developed sufficient to cause empty capsules and capsule parts to be drawn into the exhaust aperture and prevented from passing through the tunnel means.
 2. A shell remover according to claim 1 wherein the exhausT aperture means is positioned downstream of the midpoint between the open ends of the tunnel means.
 3. A shell remover according to claim 1 including means of adjusting the size of the tunnel end openings. 